FIELD OF THE INVENTION
This invention relates to an electrical control or signalling device such as a push button or lamp or analogous device including a dialogue element intended to be fixed on one side of a support wall, this element being extended by a tubular part to be engaged in an orifice in the wall in order to receive, from the other side of the wall, means of attachment to the wall and an electrical unit such as a switch contact block or an auxiliary unit.